I've a PXFmini + RPiO setup. It was working properly and I was trying to have the Compass of my GPS ublox working when when it turned out that when I power up my QuadCopter the ArduCopter starts crashing constantly. The log file looks like:

pi@erle-brain-2 /home/erle $ more APM/info/copter.log Argument is not valid. Fallback to console.Launch with --help to see an example.0 0 0 ? Raspberry Pi 1 with BCM2708!Interrupted: Segmentation faultArgument is not valid. Fallback to console.Launch with --help to see an example.0 0 0 ? Raspberry Pi 1 with BCM2708!Argument is not valid. Fallback to console.Launch with --help to see an example.0 0 0 ? Raspberry Pi 1 with BCM2708!Argument is not valid. Fallback to console.Launch with --help to see an example.0 0 0 ?

If I start the process directly after doing sudo systemctl stop apm.service

I've installed the firmware by flashing the SD card initially with your frambusea OS and then yesterday when it start failing I've done an sudo apt-get purge -y apm-copter-pxfmini followed by sudo apt-get install apm-copter-pxfmini but it has not changed anything about the issue.

I've checked several times the weldings. The way the firmware is crashing is still exactly the same. I can't believe it is still due to a welding problem. I've started reflashing the SD card with you frambusea image and re-installing the firmware. I'll let you know when I'll try it.After doing all that, I've no idea what to do next.

After re-flashing the frambuesa and doing a clean install of the APM software it does not crash anymore.

When my problem started, I was trying to install a uBlox GPS with compass and was trying to change some parameters to have my external compass used instead of the internal one. Could it be that the parameters I've set are not good and make the APM crash? When re-installing the APM, are the parameters reseted to their default value or are they stored in a location that is not cleaned by any remove and re-install?

One additional question, after starting the APM, I've in the log the following:

Raspberry Pi 1 with BCM2708!Argument is not valid. Fallback to console.

It comes from the -C /dev/ttyUSB0 in the Arducopter.elf argument and indeed the /dev/ttyUSB0 is not existing in the system. I've reused my apm.sh script from previous installation. Is it normal? Should I remove that argument as I'm not using an USB telemetry module.

I'm a Mac user and therefore using APM Planner 2.0 in which the interface is not as complete as with Mission Planner. I've to directly change the parameters. Do you know which parameter to set to deselect the internal compass and select only the external one?